Machine for wrapping



Feb. 7, 1961 M. s. PARKS MACHINE FOR WRAPPING 4 Sheets-Sheet l Filed Jan. 3, 1956 x s R M 0 N. m w ,lil n .m Y l .||||H| w mw` IIIMI AWN m @A k GAI( /J Y l B w.. u 3 wf E l o ww n o lhH| ww n# Mw w m* Wem. wm 7, |l/ um H I ww N .uw .W #www N on E., v mh mm 4| NN WN N ww Feb. 7, 1961 M. s. PARKS MACHINE FOR WRAPPING 4 Sheets-Sheet 2 Filed Jan. 5, 1956 INVENTOR Piera/1h S Parks BY @wwf img;

Feb. 7, 1961 M. s. PARKS MACHINE FOR WRAPPING 4 Sheets-Sheet 3 Fig.5

INVE TORy Filed Jan. 3. 1956 Feb 7, 1951 M. s. PARKS 2,970,417

MACHINE FOR WRAPPING Filed Jan. s, 195e .4 sheets-sheet 4 ..75 al 3 s4 INVENTOR- Ye/w/rl 5'.' Fu'ks wmf@ United States Patent() MACHINE FOR WRAPPING Merwn S. Parks, 11520 Bothell Way, Seattle, Wash., gsignor of one-half to Theodore E. Nelson, Seattle,

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Filed Jan. 3, 1956, Ser. No. 556,860 Claims. (Cl. 53-226) This invention relates to the art ofpackaging, and especially pertains to a machine for packaging produce, particularly heads of leafy vegetables such as lettuce, and is a continuation-impart of application Ser. No. 485,118, filed Jan. 3l, 1955 and now abandoned. While the rmachine of the present invention admits of being used by a produce farmer, or in fact at any stage of handling prior to the sale of the produce to the ultimate consumer, the primary purpose of the invention is `to provide a machine for use by grocers at the retail level enabling the grocer, after rst preparing his heads of lettuce by removing surface leaves whichare discolored or withered, to then package the preparedjheads in individualwrappers of cellophane or other like or suitable material, the cellophane wrappers protecting the lettuce by sealing the same from the atmosphere and additionally giving the contents an unusually attractive appearance. A

A further and important object is to provide such a machine as admits of using, for the wrappers, flat sheets of cellophane, and wherein the machine draws the edges of these at sheets up and around the head of lettuce, gathers these edges together, and heat-seals the gathered edges in a substantial weld or fusing action.

As a further object still the invention aims to provide a structure iniwhich a device electrical in nature supplies the energy responsible for activating the structure through a cycle of operation, and in which a normally incomplete electric circuit including'said device is completed by the closing of a manually operated switch and is broken automatically upon the completion of a cycle of operation.

Yet further particular objects are to provide a machine of simple and inexpensive construction, one in which the cost of operation and upkeep is nominal, yand one which is easy to work. Y Y

With these and yet additional objects and advantages in view, and which will each appear and be understood in the course of the following description and claims, the invention consists in the novel construction and in the adaptation and combination of parts hereinafter described and claimed:

In the accompanying drawings:

y Figure l is a longitudinal vertical sectional view portraying a lettuce-wrapping machine constructed in accordance with the preferred teachings of the present inven- Fig. 4 is a fragmentary horizontal sectional View drawn4 on line 3 3 of Fig. l.

Figs. 5, 6 and 7 are schematic views illustrating the machine at three stages of its operations; and

. Fig. 8 is a diagram of the electric wiring hook-up forl the machine. Y

2,970,417 Patented Feb. 7, 196.1

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Before proceeding with a detailed description of the invention it is here pointed out that my illustration of, and reference to, a head of lettuce as the article to be wrapped is by way of example Vonly in that the machine self-evidently has wide usage insofar as adapting itself to the wrapping of various and sundry items. I intend that the term lettuce is to be given a generic meaning in each instance of its occurrence both in the description and in the claims and that the same will in no way be so construed as to place a limitation on the nature of the article for which the machinesV wrapping oiiice is to be performed.

Referring to said drawings, the numeral 19 designates a casing which is or may be of a rectangular plan configuration, open at the sides, and with a table 20 secured in spaced paralleling relation above the upper wall 21., having registering openings 22 and 23 in said table near side, front wall considered, of the entrance open- A and top wall giving access to a basket 24 which is ar ranged to support the head H of lettuce while the wrapping is being performed, and providing a discharge opening 25 in the front wall 26.

27 and 28 denote plates heated by electric elements 30 yand 31 and serving as the jaw complements of a hot press. Of these two complements the jaw 27 is stationary and occupies a position immediately below and at the ing 23. The jaw 28 is movable, with its travel being reciprocal across the opening 23 into and out of a closed position, whereat the same approximately engages the stationary jaw, from a normal inactive position at the far side of such opening. The path travelled by said movable jaw is arcuate in that the same is secured to the head end of a leg 32 pivoted at the substantial base ofthe machine for fore-and-aft swinging movement about a transverse horizontal axis in the plane of a perpendicular passing through a diameter of the opening 23. Horizontal slots 33 extend along each side of the movable jaw 28, and slots 34 are also provided along each side of the stationary jaw 27. Two arms 35 and 36 pivoted, as at 37 and 38, for opposed horizontal swinging movement about a respective vertical axis are held by rollers 40 and 41 in the slots of the movable jaw and by forward travel of said jaw as the same swings with the leg 32 are brought inwardly from the full-line open position to the dotted-line closed position shown in Fig. 3, the free ends of said arms being caused in, said closed position to enter the side slots 34 of the stationary jaw. 42 denotes a thermostatic switch responding to the temperature condition of the stationary jaw 27, and as will be noted from an inspection of the wiring diagram, hereinafter to be described, this switch also controls the energizing of the heating element in the jaw 28.

Considered in side elevation said leg 32 has much the shape of a chair in that there is provided a seat-like offset 43 within its length, and bearing against this offset is a knee-shaped tongue 44 prolonged rearwardly and upwardly from a kick-frame 45 journaled for vertical sliding movement on posts 46 dropped from each of the four corners of a plate 47 riveted to the underside of the basket 24. Springs 48 and 49 received upon the posts above and below the kick-frame normally locate the latter in a floating balanced condition. The free end of the tongue is rolled to produce an eye 50, and received for pivotal movement through this eye is the cross-arm 51 of an inverted-U standard 52, the standard having its lower end-hinged to a pin 53 so as to.- admit of foreand-aft swinging movementY about a transverse hori zontal axis. A sear spring 54 taking a purchase fromY of the casing is a worm wheel powered by a worm 56 from an electric motor 57, and driven in unison with such worm wheel about a coinciding axis is a power Wheel S. Functioning as a cam for a roller 59 carried by a switch arm 69, hereinafter to be more particularly described, the perimeter 69 of the power wheel is concentric to the rotary axis excepting for a single notch 63,. 62 denotes a crank pin carried by the power wheel, and connecting with this crank pin is a pitman arm 63 having its free end passing through a hole formed in the leg 32. A collar 64 xed to said free end bears against the outer face of the leg, and bearing against the inner face is a nose-piece 65 slidably journaled upon the pitman arm and subjected to the yielding thrust of a compression spring 66.

It will be apparent that an approximate one-third revolution of the power wheel from the position in which it is shown in Fig. l acts through the pitman arm to push the leg 32 forwardly, and as this motion occurs the knee-shaped tongue 44 by force of the spring 54, rides upwardly along the sloping offset of the leg, Iesponsively drawing the standard 52 from its normal rearwaroly inclined position into an approximately vertical position. Upon reaching this vertical position, and which occurs more or less coincident with the movement of the leg 32 to the forward limit of its reciprocal travel, a keeper 67 (see Fig. 4) is shifted by action of a spring 68 into an interruptive position behind the latter. So positioned, the keeper precludes the standard from returning to its normal rearwardly inclined position as such standard, by return motion of the leg 32, is relieved of the pressure which was responsible for moving the same forwardly, namely the pressure from the off-set 43 against the tongue 44. The keeper is in the nature of a bell-crank pivoted as at 7u for rocker movement about a vertical axis, and said spring transmits its force to the keeper through a push-pull rod ift extending longitudinally of the casing. keeper, is obtained by a bob-arm 72 caused to be engaged by the pitman arm as the latter approaches the rear extreme of its reciprocal movement, the bob-arm being pivoted, as at 73, for rocker movement abouta transverseA horizontal axis.

Included in the present machine so as to prevent an overrunning action of the power wheel upon a de-energiz ing of the electric motor is a brake shoe 74 actingqupon a drum surface 75 integral with the armature shaft '76. A spring 77 (see Fig. 8) normaliy urges the shoe against the drum. rIhe brake is released by the energizing of a normally inactive solenoid '73.

Now describing the electric circuit, it will be seen that there are two manually operated 2pole switches 86 and 3l, the former being a master switch and the latter a control switch by which the machine is caused to work through one cycle of operation. Power from a main line S2 is delivered to one pole of the master switch, and from the other pole a lead line S3 connects with one side of a thermostatic switch 84. Lead lines 8S and S6 including the heating element 39 and lead lines 87 and 38 including the heating element 3l con neet the other side of the neutral 89. Y

From the lead line 83 respective connections vare made by lead lines 95 and 9i one with one pole of the control switch and the other with one pole of a switch 92 associated with the hereinbefore mentioned switch arm 66. Each of these latter two switches are brought into two series circuits, one with the electric motor 57 and the other with the solenoid 7S. More especially, the series circuit from switch 81 through motor 57 includes lead lines 93, 94 and 9S. The series circuit fromswitch 92 through said motor includes lead lines 96, 97, 94 and 95. The series circuit from switch 81 through the solenoid 78 includes lead lines 93, 96, 98 and 99. The series Pull force, for tripping the thermostatic switch with a d circuit from switch 92 through the solenoid includes the lead lines 93, 97, 98 and 99.

Now tracing the operation of the machine, the proicedure is as follows: Having previously closed the master switch 30 and allowed the plates 27 and 28 of the hot press to reach operating temperature, the operator places a sheet S of cellophane or. other like or suitable transparent Wrapping material over the opening 22 and then places the head H of lettuce onto this sheet, the head dropping through the hole into the basket and causing the wrapper to assu-me much the shape and position in which it is shown in Fig. 5. The operator thereupon closes the control switch 8l, leaving the same closed only until the motor has started, which perforce initiates a rotation of the power wheel 55 and a responsive closing of switch 92 as roller 59 is lifted onto the concentric cam surface 69. Leg 32 now moves forwardly and coincidently draws the arms 35 and 36 toward one another as the jaws close, the closing action being completed when the pitman arm has movedthrough approximately one-half of its forward stroke of reciprocation. free edge portions of the wrapper around the top side of the head of lettuce and such gathered edge portionsk are heat-sealed by the hot press in a substantial fusing action. During such fusing or welding of the transparent plastic the continued forward travel of the pitman arm subjects the movable jaw 28 to a continually increasing spring load from the compression spring 66. Now, as the pitman arm commences its return travel, bearing in mind that the standard 52 isv held in a substantially vertical position by the keeper 67, the offset 43 of the leg 32 is retracted from the tongue d4, and the basket tips into the position sho-wn in Fig. 7 and the wrapped head is discharged thrrough the opening 25. l

The invention and the manner of its functioning should be clearly understood from the foregoing detailed description of my now preferred illustrated embodiment. Permissible changes in the details of construction which can be resorted to without departing from the spirit of the invention will largely suggest themselves and it is accordingly my intention that no limitations be implied and that the hereto annexed claims be given -a scope fully commensurate with the broadest interpretation `to which theemployed language admits.

What I claim is:

1. In a wrapping machine, a basket arranged to receive and support a sheet of fusible wrapping material with a head of lettuce thereon, electrically heated opposed, plates functioning as the jaw complements of a hot press mounted for opening and closing movements immediately above the basket, two arms working with the jaws of the hot press in opposed paths approximately at right angles to the path of travel of the jaws for gathering side edges of the wrapping sheet to enable the jaws to close upon the same and fuse the gathered edges together, a source of power, and means driven from said power source and having operative connection with the jaws and with the arms causing the jaws and the arms to operate in concert.

2. In a wrapping machine, a basket arranged to receive and support a sheet of fusible wrapping material with a head of lettuce thereon, electrically heated opposed plates functioning as the jaw complements of a hot press mounted for opening and closing movements immediately above the basket, two arms working with the jaws of the hot press in opposed paths approximately at right angles to they path of travel of the jaws for gathering side edges of the wrapping sheet to enable the jaws to close upon the same and fuse the gathered edges together, a con nection between the jaws and the arms causing the arms to move inwardly in the performance of their gatheringA oiiice automatically in concert with a closing movement of the jaws, and means powering said jaws.

3. In a wrapping machine, a basket arranged to receive and support a'sheet of fusible wrapping material with a head of lettuce thereon, electrically heated op- This closing action gathers the` posed plates functioning as the jaw'complements of a hot press mounted for opening and closing movements immediately above the basket, two arms working with the jaws of the hot press in opposed paths approximately at right angles to the path of travel of the jaws for gathering side edges of the wrapping sheet to enable the jaws to close upon the same and fuse the gathered edges together, a connection between the jaws and the arms causing the arms to move inwardly in the performance of their gathering oice automatically in concert with a closing movement of the jaws, a rotary power wheel, and means driven by said power wheel and acting in each revolution thereof to move the jaws through a complete cycle of operation.

4. In a wrapping machine, a basket arranged to receive and support a head of lettuce lying on a sheet of fusible wrapping material of a size such that the edges of the sheet project well beyond the rim of the basket, heated opposed plates functioning as the jaw complements of a hot press mounted for relative opening and closing movements immediately above the basket-supported lettuce head, opposed means movable inwardly and outwardly at opposite sides of the path travelled by the jaws for gathering the projecting edges of the Wrapping sheet to enable the jaws to close upon the same and fuse the gathered edges together, a source of power, and operative interconnection from the power source both to the jaws and to the gathering means for activating the gathering means in the performance of their gathering otice and at the same time closing the jaws upon the edges of the wrapping sheet gathered by said gathering means.

5. In a wrapping machine, a basket arranged to receoive and support a head of lettuce lying on a sheet of fusible wrapping material of a size such that the edges of the sheet project well beyond the rim of the basket, heated opposed plates functioning as the jaw complements of a hot press mounted for relative opening and closing movements immediately above the basket-supported lettuce head, opposed means movable inwardly and outwardly at opposite sides of the path travelled by the jaws for gathering the projecting edges of the wrapping sheet to enable the jaws to close upon the same and fuse the gathered edges together, means for activating the gathering means to cause the same to gather the projecting edges of the wrapping sheet, and means for activating the jaws to cause the same to close upon the gathered edges of the wrapping sheet, the basket being pivotally mounted for reciprocal swinging motion between two poistions one of which is an approximately level position in which the Wrapping operation is performed and the other of which is a tilted position causing the wrapped lettuce to discharge itself from the basket.

References Cited in the le of this patent UNTED STATES PATENTS 827,285 Ballard July 31, 1906 980,329 Northup Ian. 3, 1911 2,016,650 Pedersen Oct. 8, 1935 2,542,135 Habgood Feb. 20, 1951 2,700,855 Ketchpel Feb. 1, 1955 2,838,897 Ponten et a1. June 17, 1958 

